The present invention relates generally to particle refining processes such as paper pulp manufacturing and more particularly to an apparatus and method for controlling a particle refining process in response to detected electron transfer phenomena.
In various refining processes, particles, including fibers and chips, must be subjected to mechanical treatment before they can be made into a finished product. For example, in manufacturing paper, cellulosic fibers must be ground or otherwise refined to make paper pulp which is then formed into paper webs or the like. This treatment may be applied in a number of different ways, but it generally includes a bruising, rubbing or crushing action on the fibers. The terms "beating" and "refining" are used in the paper industry to describe the operation of mechanically treating wood chips and pulp fibers. Refining usually refers to a fiber separation and subsequent fiber wall separation, i.e., primary, secondary and tertiary refining.
In one type of refining used in the paper industry and referred to as "disk refining", two parallel disks rotate relative to one another with a space therebetween. The surfaces of the disks have refiner plates mounted thereto which provide a refiner surface and define the refiner gap. The refiner plates have a precise configuration of angled bars and grooves so that wood chips or pulp fed into the gap will be subjected to a refining action. The distance between the refiner plates (i.e., the gap size) and the pressure exerted on the material being refined can be regulated to vary the degree of refining action. An example of such a disk refiner is provided in U.S. Pat. No. 4,454,991 issued June 19, 1984 and entitled "Apparatus and Method for Monitoring and Controlling a Disk Refiner Gap."
It is known that the degree of refining action in particle refining processes will influence the end product produced from the refined material. However, there has heretofore been no convenient way to predict the quality of the output from a particular refiner run without physically sampling the refined product and subjecting the sample material to physical and/or chemical tests.
It would be advantageous to provide an apparatus and method that would enable real-time ongoing monitor and control of a particle refining process without the need to test actual samples of the material being refined. It would be further advantageous to provide such an apparatus and method without the need to make any physical contact with the material being refined. Such "non-invasive" monitoring and control of the refining process would enable the benefits provided thereby to be realized without the need to modify existing refining machines.
The present invention relates to such an apparatus and method.